Sedimentary Rock (Metamorphosed)

Gold-bearing quartz vein rock (likely pyrite-rich quartzite)

Quartz (SiO₂) with iron sulfides, chiefly pyrite (FeS₂), possibly chalcopyrite (CuFeS₂); gold cannot be confirmed visually

Likely weathered granite or granitic gneiss

Granite–gneiss, composed mainly of quartz, feldspar, and mica/amphibole

Quartz-rich sandstone or quartzite cobble

Quartz arenite; possibly weakly metamorphosed quartzite (SiO₂-dominant)

Weathered quartz-rich metamorphic rock

Likely quartzite or quartz-veined metamorphic rock, chiefly SiO₂ with iron-oxide staining

Dark gray rock fragment (tentative basalt or slate)

Indeterminate; possibly fine-grained basalt, or metamorphic slate

Quartz-rich rock, likely quartzite

Quartzite; predominantly microcrystalline quartz (SiO₂), possibly with mica or feldspar impurities

Tumbled yellow-brown quartzite or jasper

Quartzite, predominantly microcrystalline quartz (SiO₂), possibly iron-stained jasper

Weathered iron-stained quartzite or sandstone cobble

Quartzite (quartz-rich rock), possibly ferruginous sandstone

Graphite-rich schist (probable)

Graphite schist; primarily graphite (C) with mica and quartz

Weathered banded iron formation (iron-rich quartzite)

Banded iron formation (BIF), chiefly hematite/magnetite and microcrystalline quartz (SiO₂)

Aventurine

Quartz (Aventurine variety)

Green-and-gold apatite-bearing rock, possibly epidote skarn

Apatite-group mineral, commonly fluorapatite (Ca₅(PO₄)₃F), with probable epidote and quartz; exact identification requires testing

Zebra Jasper

Tectonized Jasper (Silicon Dioxide, SiO2)

Map Jasper (Grey Picasso Jasper)

Silicon Dioxide (SiO2) with impurities

Quartz-rich rock, likely milky quartz or quartzite

Quartz (SiO₂), possibly quartzite if metamorphically recrystallized

Quartz-veined metamorphic rock, likely greenschist or altered basalt

Chlorite–actinolite schist or metabasalt with a milky quartz vein

Shale (possibly)

Shale (fine-grained clastic sedimentary rock)

Iron-stained quartz-rich rock, possibly jasper/quartzite

Quartz (SiO₂) with iron-oxide staining; likely ferruginous quartzite or jasper

Weathered iron-rich metamorphic rock, likely schist or quartzite

Provisional identification: ferruginous quartzite or mica schist; composition likely quartz (SiO₂), iron oxides/hydroxides, and mica or clay minerals

Iron-stained quartzite (likely)

Quartzite, predominantly quartz (SiO₂), with iron-oxide staining and possible mica/feldspar

Inspirational River Stone (Quartzite)

Metamorphosed Quartz-rich Rock (Quartzite) with SiO2 composition

Likely granite or granitic gneiss pebble

Granite: quartz + feldspar + mica; possibly gneiss if the minerals show layering

Banded Iron Formation (BIF)

Banded Iron Formation (Taconite/Itabirite)

Dark gray foliated metamorphic rock, likely slate or phyllite

Slate/phyllite; commonly quartz, muscovite/illite, chlorite, and graphite or carbonaceous matter

Iron-stained Quartzite

Metamorphosed Quartz (SiO2) with Hematite/Limonite impurities

Rounded quartz-rich cobble, likely granite or granitic gneiss

Granite/granitic gneiss; mainly quartz, feldspar, and mica

Banded sandstone or quartzite fragment

Quartz-rich sandstone; possibly weakly metamorphosed quartzite

Rounded brown river pebble

Likely weathered quartz-rich sandstone or iron-stained quartzite; exact identification requires testing

Tumbled dark quartzite or basalt pebble

Likely fine-grained basalt (plagioclase–pyroxene), though quartzite is possible from the image

Quartz-rich breccia or iron-stained quartzite

Silica-rich rock dominated by quartz (SiO₂), with minor iron oxides and possible feldspar

Foliated slate or phyllite

Fine-grained metamorphosed mudstone; typically quartz, mica, chlorite, and clay-derived minerals

Quartzite with Iron Inclusions

Metamorphosed Quartz-Rich Sandstone (SiO2 with Fe2O3)

Weathered sandstone or iron-stained quartzite

Quartz-rich sandstone; possibly weakly metamorphosed quartzite (SiO₂-dominant)

Rounded gray river cobble

Likely fine-grained sandstone, siltstone, or metamorphosed equivalent; exact identification requires a fresh surface and tests

Greenstone pebble

Likely chlorite- or epidote-bearing metamafic rock (metabasalt/greenschist)

Weathered quartz-rich pebble (likely milky quartz or quartzite)

Quartz, silicon dioxide (SiO₂); possibly quartzite, a metamorphic quartz rock

Rounded greenish river pebble

Likely altered basalt or greenstone (metabasalt); exact identification requires testing

Graphite-bearing schist (probable)

Graphite–quartz–mica schist; chiefly graphite (C), quartz (SiO₂), and mica

Slate

Metamorphosed Shale (Fine-grained Foliated Metamorphic Rock)

Quartzite River Stone

Metamorphosed Quartz-rich Sandstone (SiO2)

Polished banded ironstone (likely magnetite-rich)

Banded iron formation (BIF), chiefly quartz/chert and magnetite (Fe₃O₄), possibly hematite (Fe₂O₃)

Quartz-rich quartzite or silicified stone

Quartzite; predominantly microcrystalline quartz (SiO₂), with minor iron-oxide staining and possible feldspar/clay impurities